In recent years, the connection ports compatible to universal serial bus (USB) protocol are widely applicable to a variety of portable electronic products, such as mobile phones and digital cameras. If there is a need to charge these portable electronic products by power, the charging power is inputted to the portable electronic products via USB connection ports which is adapted to a dedicated charger device or connected to USB ports of the computer system. Based on USB version 2.0, the charging current provided by the USB connection port has a range from 100 milliampere (mA) to 500 mA. When the electronic products are charged by the USB ports of the computer system, only the maximum charging current, i.e. 500 mA, is provided to the electronic products for battery charging, which results in a slow charging status and thus takes a lot of charging time. A part of battery charging standards of portable electronic products allow the computer system and hub to supply higher charging current in order to reduce the charging time of portable electronic products.
However, due to the consideration of production cost, the connection ports having higher power supply ability in the computer system which are provided to the hub are limited and the connection ports are only the specific ports. Therefore, when the portable electronic products are inserted to the connection ports without higher charging current, the portable electronic products cannot be rapidly charged and lack the charging usage flexibility.
To solve the aforementioned problems, an Electrically Erasable Programmable Read-Only Memory (EEPROM) is conventionally proposed to store the arrangement status which indicates the chargeable connection ports in higher charging current. The hub reads the arrangement status in the EEPROM to solve the problem of the charging usage flexibility of the specific ports. However, this case increases the manufacturing cost of the EEPROM.
In another conventional technique, each of connection ports has an additional pin in the hub controller and the hub controller determines whether the connection ports with the pins are the chargeable connection ports based on the higher charging current. However, the size of integrated circuit (IC) is very precise and the occupied area of IC considerably shrinks. As a result, it is quite difficult to add pins on the IC and the manufacturing cost is increased even if the pins are added.
Consequently, there is a need to develop a charging system with higher charging current for the portable electronic products to solve the aforementioned problems.